In his 2016 campaign for senate against incumbent Sen. Roy Blunt, R-Mo., Kander set himself apart from Democratic presidential candidate Hillary Clinton by opposing her call to add a public option to the Affordable Care Act.

"For years Democrats were scared to make an argument for Obamacare," Kander said over the weekend. "For whatever reason, folks all over the country were scared to lean all the way into it."

He added that Republicans' failure to follow through in their vow to repeal and replace Obamacare proves that it's time to "embrace universal healthcare."

"We made the argument, and we saw an important victory that will save lives because we made the argument," Kander said. "So we shouldn't stop making that argument. Where we should go from here is take that energy and we should be honest about what we believe. What we believe is that healthcare should be a right in this country; I happen to believe that means that we should be for single-payer."